Thanks a lot for these tips, Wayne - had a long & hot day today and just
became aware of your answer, while waiting for the sun to rise, awake
all night long ;-)
Fernando
WayneS wrote:
> At 11:00 PM 11/24/2008, Fernando wrote:
>
>> ...
>> Also, I've just learned what could be old news for you the experts:
>> sharpening using brightness channel in LAB mode.
>>
>
> This is one of my standard techniques as I like to use Lab mode.
> Luminance sharpening can work better if there is noise in the image.
> It helps avoid increasing chroma noise and chromatic aberration
> along edges.
>
> I suspect there is a way to do the equivalent in RGB, perhaps with
> a luminance blend mode of a another layer? But that may not
> work as well as Lab mode at preventing color side effects
> along the edges.
>
> For example, creating an edge mask from a channel that is created
> from RGB luminance, then blend using luminance.
> ... all speculation on my part as I have never tried this.
> As with anything Photoshop, there are many ways to do things.
> Here is an interesting method:
> http://photoshoptutorials.ws/photoshop-tutorials/photo-retouching/edge-sharpening.html
>
> I suspect the halo effects from sharpening are similar to over-shoot
> in filters. Only Bessel filters produce no over or under shoot in a step
> response. Bessel filters have a very smooth frequency transition.
> Very sharp filters will have over/under-shoot in the step response.
>
> Wayne
>
>
>
--
Dr. Fernando González Gentile M.D.
Av.L.P.Ponce 1526B - 11600 Montevideo, Uruguay.
Phone: +598 2 7084858
Fax: +598 2 7087396
<fgnzalez@xxxxxxxxxxxxx>
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|